Benefits of VLANs

• Broadcast Control : Broadcasts are needed for the regularly function of a network . Many protocols and application rely on broadcast communication to function properly . A layer 2 switched network is basically in a single broadcast domain and the broadcasts can reach the network segments which are so far where a particular broadcast has no scope and consume available network bandwidth . A layer 3 device ( typically a Router ) is utilized to segment a broadcast domain .

If we segment a large LAN to smaller VLANs we will reduce broadcast traffic as each broadcast will be sent on to the relevant VLAN only .

• Security : VLANs present enhanced network security . In a VLAN network environment , with multiple broadcast domains , network administrators have control over each port and user . A nasty user can no longer just connect their workstation into any switch port and sniff the network traffic using a packet sniffer . The network administrator controls each port and whatever resources it is allowed to use .

VLANs make it easier to restrict vulnerable traffic originating from an enterprise department within itself .

• Cost : Segmenting a massive VLAN to smaller VLANs will cost less than creating a routed network with routers because normally routers costlier than switches .

• Physical Layer Transparency : VLANs are transparent on the physical topology and also medium over which the network is connected .